[PATCH] MdeModulePkg PiSmmCore: Unregister each other for LegacyBoot and EBS

[Star Zeng <star.zeng@intel.com>]

Otherwise, LegacyBoot may be triggered wrongly by other code in UEFI OS,
or vice versa.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdeModulePkg/Core/PiSmmCore/PiSmmCore.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c b/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
index 6d266933868d..d516e9dcea34 100644
--- a/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
+++ b/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
@@ -157,6 +157,7 @@ SmmLegacyBootHandler (
 {
   EFI_STATUS    Status;
   EFI_HANDLE    SmmHandle;
+  UINTN         Index;
 
   //
   // Install SMM Legacy Boot protocol.
@@ -173,6 +174,16 @@ SmmLegacyBootHandler (
 
   SmiHandlerUnRegister (DispatchHandle);
 
+  //
+  // It is legacy boot, unregister ExitBootService SMI handler.
+  //
+  for (Index = 0; mSmmCoreSmiHandlers[Index].HandlerType != NULL; Index++) {
+    if (CompareGuid (mSmmCoreSmiHandlers[Index].HandlerType, &gEfiEventExitBootServicesGuid)) {
+      SmiHandlerUnRegister (mSmmCoreSmiHandlers[Index].DispatchHandle);
+      break;
+    }
+  }
+
   return Status;
 }
 
@@ -201,6 +212,7 @@ SmmExitBootServicesHandler (
 {
   EFI_STATUS    Status;
   EFI_HANDLE    SmmHandle;
+  UINTN         Index;
 
   //
   // Install SMM Exit Boot Services protocol.
@@ -215,6 +227,16 @@ SmmExitBootServicesHandler (
 
   SmiHandlerUnRegister (DispatchHandle);
 
+  //
+  // It is UEFI boot, unregister LegacyBoot SMI handler.
+  //
+  for (Index = 0; mSmmCoreSmiHandlers[Index].HandlerType != NULL; Index++) {
+    if (CompareGuid (mSmmCoreSmiHandlers[Index].HandlerType, &gEfiEventLegacyBootGuid)) {
+      SmiHandlerUnRegister (mSmmCoreSmiHandlers[Index].DispatchHandle);
+      break;
+    }
+  }
+
   return Status;
 }
 
-- 
2.7.0.windows.1